1. Field of the Invention
The present invention relates to an improvement in a leader tape or trailer tape for a magnetic tape and more particularly, it is concerned with a novel structure of a leader tape or trailer tape situated at the head portion or tail portion or, if necessary, intermediate portion of a long tape for magnetic recording such as video tapes, memory tapes or audio tapes.
2. Description of the Prior Art
It has hitherto been considered that the phenomenon of drop out occurring in a magnetic tape section is mainly due to the magnetic tape itself, but it has been found by our studies that this drop out is due to the leader tape and, when the surface electric resistance or electrostatic charge potential of the leader is low, the drop out is decreased. It has also been found that clogging of a rotating video head is due to a leader or trailer tape in addition to a magnetic tape. As the antistatic treatment of a tape-shaped material, it has been proposed (1) to coat the surface thereof with an antistatic agent and (2) to lower the electric resistance of the whole of layers.
With respect to the leader tape or trailer tape, there have hitherto been made various proposals, for example, comprising (1) providing a metallic vapor deposition in the form of a stripe (Japanese Utility Model Publication No. 14349/1971), (2) matting one or both sides of a base (Japanese Utility Model Publication No. 42726/1974) and (3) providing a coating layer containing 50 to 800 parts of a pigment having a grain size of 4 microns or less per 100 parts of a binder (Japanese patent application (OPI) Nos. 40504/1974 and 67603/1974). Above all, the proposal (3) is more preferable, but still has the following disadvantages: (1) The surface electric resistance or electrostatic charge potential cannot be lowered, (2) Head clogging occurs and (3) Blocking occurs at a high temperature and high humidity.